\documentclass{article}
\usepackage{amssymb,amsmath,amscd,concmath}
\pagestyle{empty}
\begin{document}
\begin{equation*}\forall x \in X,  \forall \epsilon > 0,  \exists y  \in X  s.t. || x - y || < \epsilon\end{equation*}
\end{document}
